Image enhancing method, device, apparatus and storage medium

Abstract

The present invention relates to an image enhancing method, a device, an apparatus and a storage medium. In the image enhancing method, first, the luminance component and the chrominance component of the image are separated and extracted, and then the ambient illumination information in the luminance component is extracted to obtain the illumination component. The luminance image is subjected to luminance correction using the illumination component to obtain the corrected luminance component, and the enhanced image is obtained by combining the chrominance component. Because the whole adjusting process adjusts the luminance of the image based on the ambient luminance information carried by the image itself, the luminance of the image can be adaptively adjusted, a weak light region is strengthened, a hard light region is weakened, the illumination balance is achieved, the enhancement effect is better, and the color distortion of the image is extremely small.

What is claimed is: 
     
       1. An image enhancing method, comprising:
 acquiring an image to be enhanced; 
 separating and extracting a luminance component and a chrominance component of the image to be enhanced; 
 extracting an illumination component from the luminance component; 
 performing luminance correction on the luminance component according to the illumination component to obtain a corrected luminance component; 
 synthesizing the corrected luminance component with the chrominance component to obtain an enhanced image; 
 wherein separating and extracting the luminance component and the chrominance component of the image to be enhanced comprises: determining whether the image to be enhanced belongs to a first target color space; wherein the first target color space is a color space comprising luminance; 
 if so, directly extracting the luminance component and the chrominance component of the image to be enhanced; 
 if not, converting the image to be enhanced into an image based on the first target color space and extracting the luminance component and the chrominance component. 
 
     
     
       2. The image enhancing method according to  claim 1 , wherein synthesizing the corrected luminance component with the chrominance component to obtain an enhanced image further comprises:
 performing grayscale stretching on the corrected luminance component. 
 
     
     
       3. The image enhancing method according to  claim 2 , wherein performing grayscale stretching on the corrected luminance component comprises:
 performing grayscale stretching on the corrected luminance component according to the following formula: 
 
       
         
           
             
               
                 
                   Y 
                   ″ 
                 
                 ⁡ 
                 
                   ( 
                   
                     x 
                     , 
                     y 
                   
                   ) 
                 
               
               = 
               
                 
                   
                     
                       1 
                       - 
                       A 
                     
                     
                       B 
                       - 
                       A 
                     
                   
                   ⁢ 
                   
                     
                       Y 
                       ′ 
                     
                     ⁡ 
                     
                       ( 
                       
                         x 
                         , 
                         y 
                       
                       ) 
                     
                   
                 
                 + 
                 
                   
                     
                       ( 
                       
                         B 
                         - 
                         1 
                       
                       ) 
                     
                     ⁢ 
                     A 
                   
                   
                     B 
                     - 
                     A 
                   
                 
               
             
           
         
       
       where A is the minimum gray level of the corrected luminance component Y′(x,y), B is the maximum gray level of the corrected luminance component Y′(x,y), and Y″(x,y) is the corrected luminance component after performing the grayscale stretching. 
     
     
       4. The image enhancing method according to  claim 1 , wherein the first target color space comprises: a YUV color space. 
     
     
       5. The image enhancing method according to  claim 1 , wherein extracting the illumination component from the luminance component comprises:
 extracting the illumination component from the luminance component according to the following formula:
     I ( x,y )= Y ( x,y )* G ( x,y ) 
 
 
       where Y(x,y) is the luminance component, G(x,y) is a filter function, and I(x,y) is the illumination component. 
     
     
       6. The image enhancing method according to  claim 5 , wherein performing luminance correction on the luminance component according to the illumination component to obtain a corrected luminance component comprises:
 performing luminance correction on the luminance component according to the illumination component according to the following formula to obtain a corrected luminance component: 
 
       
         
           
             
               
                 
                   Y 
                   ′ 
                 
                 ⁡ 
                 
                   ( 
                   
                     x 
                     , 
                     y 
                   
                   ) 
                 
               
               = 
               
                 
                   Y 
                   ⁡ 
                   
                     ( 
                     
                       x 
                       , 
                       y 
                     
                     ) 
                   
                 
                 
                   
                     
                       f 
                       2 
                     
                     ⁡ 
                     
                       [ 
                       
                         I 
                         ⁡ 
                         
                           ( 
                           
                             x 
                             , 
                             y 
                           
                           ) 
                         
                       
                       ] 
                     
                   
                   
                     
                       f 
                       1 
                     
                     ⁡ 
                     
                       [ 
                       
                         ( 
                         
                           x 
                           , 
                           y 
                         
                         ) 
                       
                       ] 
                     
                   
                 
               
             
           
         
       
       where f 1 [I(x,y)] and f 2 [I(x,y)] are functions of the illumination component I(x,y), and, Y′(x,y) is the corrected luminance component. 
     
     
       7. An image enhancing apparatus, comprising:
 a processor and a memory connected to the processor; 
 
       wherein the memory is configured to store a computer program;
 the processor is configured to invoke and execute the computer program in the memory to perform the steps of the method according to  claim 1 . 
 
     
     
       8. A non-transitory storage medium, wherein a computer program is stored in the storage medium, which, when executed by a processor, implements the steps of the method according to  claim 1 .